1. Field of Invention
The present invention relates to a timepiece and a portable device that have a sound source such as a gong or a bell.
2. Description of Related Art
Sonnerie timepieces that have a C-shaped gong and a hammer for striking the gong are known from the literature. See, for example, “2002 Guide to the latest wristwatches with full specifications,” K. K. Gakushu Kenkyusha, published Mar. 1, 2002, page 117. The timepiece in this example has the gong fastened to the base plate and disposed along the outside of the movement. The hammer is attached to the base plate on the inside of the gong so that the hammer can pivot, and is driven at a predetermined time by the drive power of a spring. A spring that returns the hammer that strikes the gong to its original position is also attached to the base plate.
The sonnerie timepiece according to the related art described above strikes the gong directly with a hammer, and a spring that urges the hammer toward the gong when striking the gong and another spring that pulls the hammer away from the gong and back to its original position after striking the gong are disposed to the hammer. However, in a mechanism such as this that has springs urging the hammer in two different directions disposed to the hammer, the hammer may not separate from the gong after striking the gong, and may therefore inhibit vibration of the gong, if the spring force of the spring that urges the hammer to the gong is high. On the other hand, if the force of the spring that pulls the hammer away from the gong is strong, the hammer strikes the gong with less force and the gong may not produce a good sound. It is therefore necessary to appropriately set the strength of these springs.
However, if the springs urging in opposite directions are attached directly to the hammer, adjusting the force of each spring appropriately is difficult.